Mendes rejects Hollywood's dream factory to remain centre stage in his Warehouse

Sam Mendes, Oscar winner, has come back to earth with a bang - literally. The hero of Hollywood flew back to London on Thursday night, opened the door of his flat, turned the heater on, and the boiler exploded.

He had to spend the night at a friend's and yesterday was back at the Donmar Warehouse theatre in Covent Garden, still in the clothes he wore on the aircraft, an old cardigan, casual sweatshirt and slacks.

But he probably would have worn something similar even if the boiler had not exploded. Mendes is keen to show that in the age-old cliché, Oscar success has not changed him. And it hasn't. He is just the same as he was before he WAS.

His main concern, chatting on the stage of the Donmar yesterday, was to talk about the coming year's programme for the theatre where he has been artistic director for the best part of a decade.

And he disclosed that in his determination to get back to directing plays after a two-year break, he had turned down a multi-million-dollar deal from Steven Spielberg's DreamWorks company - the one behind Mendes's Oscar-winning film American Beauty - to direct a package of movies.

Mendes will not even think about directing another film for at least a year. But - and this was the bombshell that he dropped yesterday - Spielberg has funded him to the tune of £250,000 a year for at least two years to set up a film office attached to the theatre. Donmar Films, staffed by just two people, was already up and running yesterday. It will receive scripts and development projects for Mendes to look at. And as soon as he decides one is ripe for filming, he will be the director under the Donmar and DreamWorks banner.

"It's a first-look deal," said Mendes. "DreamWorks are funding me to develop a few projects which they get first look over. I wanted it connected to the Donmar geographically and philosophically. Steven and all of DreamWorks are aware of what they are part of and they are thrilled."

Mendes and Caro Newling, his executive producer at the Donmar, have also persuaded Spielberg to give £100,000 a year for three years to the theatre itself. The pair are rapidly becoming a canny negotiating team, having wooed New York producer Anita Waxman to give £220,000 to the theatre, also for three years. With public subsidy of £251,000 on top, the days of Mendes demanding more money from the Arts Council seem long gone.

But Mendes knows that he could be sitting on much bigger money. If anyone is hot, he is. He laughed as he confirmed this by saying that there was a gala fund-raising performance of Tom Stoppard's play The Real Thing (a Donmar production) in New York next week. And suddenly American movie big shots Harvey Weinstein, Jeffrey Katzenberg and Sydney Pollack have all bought tables - "the three biggest tables", he added.

And even Mendes, the usual theatre-director mixture of self-effacing modesty and an utter control freak, admits that he is not short of big money offers at the moment. "If I had signed an exclusive deal with DreamWorks I could have got millions. But I wasn't interested in being tied down or not being able to do theatre. I wanted to make sure I wasn't waiting in a vacuum, flying backwards and forwards."

He added that he had seen how his friend and fellow director Anthony Minghella had almost a five-year wait between The English Patient and The Talented Mr Ripley. Mendes is determined not to become the servant of a big studio.

For American Beauty, Mendes only got a fee rather than a percentage, but he agrees that the next movie is the one where he will earn real money. Or as he puts it: "I will make not very much money from American Beauty, but obviously my rate has gone up recently. But I couldn't start shooting a movie till next spring at the earliest."

Nevertheless, scripts are already pouring through the door. "I'm being sent a lot of stuff, more than I can cope with, for some reason," he joked. "Now is the time to make my crusades epic for $120m. Right now I think they would say yes to anything I suggest... But I don't desire to become part of the Hollywood community."

He has, though, been looking at one script, The Lookout by Scott Frank, who wrote Get Shorty.

For a while, Mendes will not miss the miscroscopic attention on his life, stories years after the event about his parents' divorce when he was young, his alleged identification with the difficult family relationships in American Beauty and his modelling the teenager's bedroom on his own, his dating of and splitting up with actresses Jane Horrocks, Claire Skinner and Calista Flockhart - all the personal stuff that goes with the territory of an Oscar nomination, right down to his batting averages.

"It was strange, especially for a theatre director," he reflected, "because we're used to watching people. Being watched is very disconcerting. I reassured myself that it's not something that is going to continue for the rest of my life. As a director, you're used to being a control freak. And then there's this whole six-week period when you do not have one iota of control. Sometimes it was exhilarating. Sometimes I had to grit my teeth."

And so back to the Donmar. Mendes's first production in the autumn season will be Shakespeare's Twelfth Night, yet to be cast. He promises it "will not be a traditional production". That will be followed at Christmas by what he terms "one of the great undone Stephen Sondheim musicals", Merrily We Roll Along, which will be directed by Michael Grandage. And this time next year the Donmar will put on a new play by Patrick Marber, possibly directed by Mendes, possibly by the author.

The obvious question, will Mendes be wooing Nicole Kidman back to the theatre, gets a surprising answer: "It's becoming more likely that Nicole will come back." He has become close friends with Kidman and Tom Cruise and she wants to work at the Donmar again.

But, although Hollywood actors have literally been knocking on Mendes's door, few will be appearing at the Donmar. "I'm nervous about star vehicles," he said. "If you have too big an event, the other shows seem reduced by comparison. But people are asking all the time. I won't name names, but they see coming here as a way of increasing their validity."

Mendes admits he has been through an intense experience and it will be hard to come down. "There's no question that the next couple of weeks I might think what do I do now? Winning an Oscar is the single most nerve-racking experience. It's way out there on its own as an adrenalin rush."

Asked by someone whether he will be putting the Oscar "in the small room", Mendes looks baffled, pauses, then exclaims: "Oh, you mean the toilet. Is that what they call it, the small room?" In fact the statuette is going in his living room.

But he must be the only Oscar winner in recent years, perhaps ever, whose heart does not seem to be in the movies at all, but in small if influential theatre space. "I'm on a rolling one-year contract at the Donmar. At the moment I'm creating an environment in which I want to work, quite selfishly. Why would I leave?"